Soft expansion type wall rock tunnel support method

Abstract

The invention discloses a support method of a weak expansion type surrounding rock laneway, comrprising the following steps: A. the laneway is excavated according to the sectional form, an arc pit is excavated on a bottom board of the laneway, and full face injection of a thick concrete leveling course is carried out; B. high-strength prestressed anchor and prestressed anchor cable are used for supporting the surrounding rock, an anchor rod and an anchor cable are constructed, a high-strength prestressed anchor rod uses a laevo rod body without longitudinal bar and is arranged in plum blossom shape; C. a foam cushion is laid, and the full face of the laneway is tightly stuck and paved with an initial ejection leveling course, and a gap is added and preserved in case of laneway deformation; D. a first layer of reinforcement mat is hung and tightly stuck to the foam cushion, a full face sealed type steel bar grid arching is constructed, the main bar inside the grid is bonded with the first layer of reinforcement mat, and the second layer of reinforcement mat is hung on the sealed type steel bar grid arching; E. the bottom board is constructed, a cast-in-place concrete gutter is constructed at the center part of a positive arching, and rubbles are paved at the both sides of the gutter. The method solves the problems of low intensity of surrounding rock laneway, water expansion and floor heave, thereby avoiding reclamation work of the laneway and having low cost.

Description

technical field [0001] The invention relates to the field of roadway support in coal mines, and more particularly relates to a roadway support method for weak and expansive surrounding rock. This method can be used for support of expansive weak surrounding rock in mine roadway and tunnel engineering. Background technique [0002] Clay rock is one of the main lithologies constituting coal-measure strata, and mudstone, bauxite and fault gouges commonly seen are typical clay rocks. The underground tunnels built every year in my country's coal mining are hundreds of kilometers long, and a considerable part of them are built in clay rock. Clay rocks often contain clay minerals such as montmorillonite, illite, and kaolin. Montmorillonite and illite are expansive when exposed to water, while kaolin is not expansive, but is easy to soften when exposed to water, resulting in a significant decrease in rock strength. Studies have shown that: when the content of montmorillonite is ove...

AI Technical Summary

Problems solved by technology

At the same time, because the volume of this type of rock doubles after being exposed to water, the expansion and deformation pressure is huge, and the internal stress of the surrounding rock is increased. The subsidence of the bottom, side drum and roof of the roadway caused the instability of the surrounding rock of the roadway, the damage of the support structure, and the production was seriously affected.

[0003] In order to solve the technical problems of stability control and support of the surroun

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